Method and means for sealing ingot casting molds to stools

ABSTRACT

The joint or space between the open bottom mold and the supporting stool used for casting steel ingots is sealed by applying a sealing means which firmly adheres to the mold body and the stool magnetically.

mite mm Quillen, J

Met [191 1 1 Sept. 24, 1974 METHOD AND MEANS FOR SEALING INGOT CASTHNG MOLDS T0 STOOLS [75] Inventor: Albert L. McQuillen, J r., Pittsburgh,

[73] Assignee: 33 Hundred, llnc., Pittsburgh, Pa.

[22] Filed: May 16, 11973 21 Appl. No.: 360,982

[56] References Cited UNITED STATES PATENTS Dornin 249/174 UX 1,457,763 6/1923 Adams 249/174 X 1,480,191 1/1924 Wilson 164/49 1,649,522 11/1927 Gathmann 249/174 UX 2,589,766 3/1952 Bernstein 49/478 X 3,111,728 11/1963 Alderfer 49/478 3,163,898 1/1965 Demaison 249/174 3,206,154 9/1965 Demaison 249/174 UX Primary Examiner-Andrew R. J uhasz Assistant Examiner-John E. Roethel [5 7 ABSTRACT The joint or space between the open bottom mold and the supporting stool used for casting steel ingots is sealed by applying a sealing means which firmly adheres to the mold body and the stool magnetically.

10 Claims, 7 Drawing Figures METHOD AND MEANS FOR SEALING INGOT CASTING MOLDS TO STOOLS BACKGROUND OF THE INVENTION This invention relates to the casting of steel ingots, more particularly to such casting in which open bottom" molds are supported by flat slabs, called stools, usually of cast iron. These molds conventionally are rectangular and of decreasing cross-section from bottom to top to facilitate removal of the ingots from the molds when they have cooled sufficiently.

Due to irregularities in the surface of the stools and in the bottom rim of the molds arising in the manufacture as well as caused by erosion in the use of these elements, the joint between the rim and the stool is not tight. To prevent flow of molten metal through this space, with consequent loss of metal poured if the space is great, or the development of stickers if the space isminor, various expedients have been suggested or used to seal the joint.

One such means is the provision of a split metallic ring adjacent the inner edge of the stool, which ring is adapted to expand from the pressure of the molten steel so as to fit tightly against the inner edge of the mold.

This arrangement, however, is not practicable since it requires very smooth surfaces at the base of the mold and on the stool adjacent thereto which cannot be maintained without frequent and expensive machining of those parts.

It has also been the practice to seal or caulk the space with various refractory materials which are applied to the outside periphery of the mold after it has been placed upon the stool. This procedure is not satisfactory, however, since it is difficult, and in some instances impossible, in actual practice to secure an effective an complete seal.

In order to provide a more complete seal without excessive labor and material costs, it has been proposed to place a preformed body of resilient mineral fibers between the bottom edge of the mold and the stool. This fibrous body may be in the form of a gasket of a width substantially equal to the thickness of the mold body or as a mat which extends completely across the surface of the stool within the mold opening as well as between the edge of the mold and the stool.

The following three (3) patents provide background in more detail: US. Pat. Nos. 1,649,522; 3,163,898 and 3,396,935.

DESCRIPTION OF THE INVENTION upon which such mold is supported during the casting operation.

It is a further object of this invention to reduce the formation of fins or ribs at the bottom of the ingot in the space between the mold and the stool.

Another object of the invention is to decrease mold and stool stickers.

These and other objects will become apparent to those skilled in the art from the following description and the accompanying drawings wherein:

FIG. 1 is a partially sectional view of a conventional mold and stool assembly;

FIG. 2 is a sectional view of the lower portion of a mold and stool assembly, including a seal according to the invention;

FIG. 3 is a plan view of a magnetic sealing strip according to the invention; and

FIG. 4 is a cross-sectional view of the strip of FIG. 3, taken along line 4-4.

FIGS. 5, 6 and 7 are sectional views of the lower portion of a mold and stool assembly in which various seals are shown, FIG. 6 illustrating magnetized particulates attached to the mold rim and the opposed surface of the stool when the latter two are spaced apart, i.e., before the superimposition.

In FIG. 1 there is shown, partially in section, the assembly of mold 10 and stool 12 resting upon a conventional buggy 14 which is used to move the empty mold and stool assembly from the mold conditioning or preparation yard to the teeming station where the heat is poured and then to the area where the ingots are stripped from the molds and stools.

Numeral 13 indicates the joint between the bottom rim of mold l0 and the top surface of stool 12.

FIG. 2 is a cross-sectional view of the lower portion of a mold l0, and its supporting stool 12 wherein the joint 13 is fitted with a metal-containing body or seal 15 which adheres magnetically to the mold rim and to the stool, in accordance with the invention.

This seal 15 may be a preformed strip or gasket of magnetic material of a size and shape conforming to that of the lower rim of the mold, such as represented by 15a in FIGS. 3 and 4. The exact size of such a strip 15a is not critical so long as it substantially closes and thus seals the joint. For reasons of economy, any substantial excess of the magnetic material is undesirable, however.

Being magnetic, it is relatively easy to place such a sealing strip in the desired position on the bottom rim of the mold and to retain it there until the mold has been placed upon the stool. In this assembly, the strip is firmly held against displacement by the molten metal during pouring by the combination of magnetic force which bind it to both the mold and the stool and the gravimetric force due to the weight of the mold itself.

Instead of a strip or gasket, the magnetic material may be applied to seal the joint after the mold has been placed upon the stool. In this embodiment, the magnetic material in particulate form, such as iron and steel clippings, whiskers, filings, shot and grit, is forced by a conventional pneumatic gun against the joint to form a beaded seal to either or both of the inner and outer edges, as shown in FIG. 5 at 15.

If desired, also, the magnetic materials, e.g., particulates, may be deposited in suitable thickness, e.g., as a bead, on one or both of the mating surfaces of the mold and stool and held there magnetically prior to placing the mold on the stool, at which time gravimetric and magnetic forces combine to seal effectively, as shown in FIG. 6 at 15.

The magnetic material contemplated herein may be used as such, but for greater convenience and economy, it is preferable to use it in admixture with nonmagnetic metallic and non-metallic particles, such as aluminum. sand, quartz, or other forms of silica, clay, glass, mineral wool, slag, carbon and carbonaceous materials, such as nut shells, paper, and the like. Any such mixture would, of course, include sufficient ferrous metals or other magnetic or magnetizable components that the same would be magnetizable if not inherently magnetic.

These particulate materials may be applied in the form of magnetized substantially dry pellets which are gunned into place under sufficient pressure to fill superficial gaps and to form a bead sealing the joint between the stool and the mold. FIG. 7 illustrates in a purposely exaggerated manner the consequence of gunning magnetized pellets into the joint between the stool and the mold in order to effect the sealing function.

Alternatively, in some applications it may be preferable to electromagnetize the mold, for example, thereby setting up a magnetic field to attract and hold the ferrous metal-containing pellets as they are forced against and into the joint.

Another mode of applying the magnetized ferrous metal-containing mixture is to admix the solid material with say, sodium silicate or other non-reactive suitable liquid binder, and then to force this mixture against the joint to form the seal.

When a liquid is thus used, the amount should be kept to a minimum so as to avoid possible local explosions from contact of molten metal with the liquid which might disrupt the seal.

It will be understood that the several specific embodiments described and shown herein are examples of the invention which is not limited thereto and that variations in the details of construction and application to bottom with a rim, a stool in contact with said rim and supporting said mold, and means for sealing the joint between said mold rim and said stool comprising a metal-containing body adhering magnetically to said mold rim and to said stool.

2. The combination as set forth in claim 1 wherein the metal-containing body is a strip of magnetic ferrous metal.

3. The combination as set forth in claim 2 wherein the strip is a gasket preformed to fit around the lower rim of the mold.

4. The combination as set forth in claim 1 wherein the metal-containing body is a bead comprising discrete particles of magnetic ferrous metal.

5. The combination as set forth in claim 4 wherein the bead is in contact with the inner and outer edges of the bottom rim of the mold.

6. The method for sealing the joint between the lower rim of an open bottom ingot mold and a stool for supporting said mold which comprises applying a ferrous metal-containing body to said joint and causing said body to adhere magnetically to said mold and to said stool.

7. The method according to claim 6 wherein the ferrous metal-containing body is a magnetic gasket which is held between the mold and stool.

8. The method according to claim 6 wherein the ferrous-metal containing body is a magnetic mixture and said mixture is forced under pressure against and into the joint between the mold and the stool forming a sealing bead.

9. The method according to claim 8 wherein the mixture is applied to both the inner and outer edges of the other embodiments may be made without departing joint.

from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In combination, a steel ingot mold having an open pellets. 

1. In combination, a steel ingot mold having an open bottom with a rim, a stool in contact with said rim and supporting said mold, and means for sealing the joint between said mold rim and said stool comprising a metal-containing body adhering magnetically to said mold rim and to said stool.
 2. The combination as set forth in claim 1 wherein the metal-containing body is a strip of magnetic ferrous metal.
 3. The combination as set forth in claim 2 wherein the strip is a gasket preformed to fit around the lower rim of the mold.
 4. The combination as set forth in claim 1 wherein the metal-containing body is a bead comprising discrete particles of magnetic ferrous metal.
 5. The combination as set forth in claim 4 wherein the bead is in contact with the inner and outer edges of the bottom rim of the mold.
 6. The method for sealing the joint between the lower rim of an open bottom ingot mold and a stool for supporting said mold which comprises applying a ferrous metal-containing body to said joint and causing said body to adhere magnetically to said mold and to said stool.
 7. The method according to claim 6 wherein the ferrous metal-containing body is a magnetic gasket which is held between the mold and stool.
 8. The method according to claim 6 wherein the ferrous-metal containing body is a magnetic mixture and said mixture is forced under pressure against and into the joint between the mold and the stool forming a sealing bead.
 9. The method according to claim 8 wherein the mixture is applied to both the inner and outer edges of the joint.
 10. The method according to claim 8 wherein the magnetic mixture is applied to the joint in the form of pellets. 